Plant Life Cycle: Week 1 lecture notes

Vocabulary flashcards cover key terms from Lecture 1 of SLE132, focusing on plant evolution, major plant groups, life-cycle concepts, anatomical structures, and course logistics.

Vascular Plant

A land plant possessing specialized conducting tissues (xylem and phloem) that allow internal transport of water, minerals, and nutrients.

Non-vascular Plant

A plant lacking xylem and phloem; relies on diffusion for water and nutrient movement (e.g., mosses, liverworts, hornworts).

Alternation of Generations

Plant life cycle alternating between a multicellular haploid gametophyte and a multicellular diploid sporophyte.

Gametophyte

The haploid (n) generation that produces gametes in the plant life cycle; dominant in bryophytes.

Sporophyte

The diploid (2n) generation that produces spores; dominant in vascular plants.

Bryophyte

Group of non-vascular plants (mosses, liverworts, hornworts) characterized by dominant gametophytes and lack of true roots, stems, and leaves.

Rhizoid

Hair-like structure anchoring bryophytes; not a true root and primarily used for attachment.

Gemma Cup

Small cup-shaped structure on liverworts that produces asexual propagules (gemmae) for vegetative reproduction.

Seedless Vascular Plant

Early vascular plants (ferns, horsetails, club mosses) that reproduce via spores rather than seeds.

Fern Sorus (plural sori)

Cluster of sporangia, typically on the underside of fern fronds, where spores are produced.

Xylem

Vascular tissue of hollow, cellulose-reinforced cells transporting water and minerals upward from roots.

Phloem

Living vascular tissue that distributes sugars and other organic products throughout the plant.

Gymnosperm

Seed plant whose seeds are not enclosed in an ovary; includes conifers, cycads, ginkgos, and gnetophytes.

Angiosperm

Flowering seed plant whose seeds develop inside an ovary that matures into a fruit.

Cyanobacteria

Photosynthetic prokaryotes (formerly ‘blue-green algae’) that helped raise Earth’s atmospheric O₂ from ~1 % to ~21 % and form stromatolites.

Stromatolite

Layered, fossil-like rock structure created by colonies of cyanobacteria through sediment trapping and mineral precipitation.

Endosymbiosis Theory

Hypothesis that mitochondria and chloroplasts originated when ancestral prokaryotes engulfed aerobic and photosynthetic bacteria, respectively.

Plasmodesmata

Microscopic channels traversing plant cell walls that connect cytoplasm of adjacent cells for communication and transport.

Oogamous Reproduction

Form of sexual reproduction involving small, motile sperm and large, non-motile eggs.

Sporopollenin

Highly stable polymer in spore and pollen walls that resists desiccation and decay.

Waxy Cuticle

Hydrophobic layer covering aerial plant surfaces to reduce water loss.

Haplontic Life Cycle

Life cycle dominated by a multicellular haploid stage with meiosis occurring in the zygote; characteristic of many algae.

Colonisation of Land

Evolutionary event (~500 MYA) when plants first moved from aquatic environments to terrestrial habitats.

Green Algae

Aquatic photosynthetic organisms closely related to land plants; origin of embryophytes (~470 MYA).

Charophytes

Order of green algae (e.g., Chara) considered the closest living relatives of land plants.

Sphagnum

Genus of mosses forming peat bogs; important carbon sink in global ecosystems.

Marchantia

Common liverwort genus featuring thalloid gametophytes and gemma cups for asexual reproduction.

Lycopod

Club moss belonging to phylum Lycopodiophyta; an ancient lineage of seedless vascular plants.

Whisk Fern (Psilotum)

Simple seedless vascular plant lacking true roots and leaves, possessing only stems with sporangia.

Team Research Report (AT4)

Major SLE132 assessment task (30 %) involving a slide deck (20 %) and oral presentation (10 %) on plant science research.